Conventionally, in the lock stitch sewing machine, the serger, the double chain stitch sewing machine, or the cover stitch sewing machine, etc., generally, mechanical needle threading tools and devices for threading a needle thread to a needle are widely used. Besides, the pneumatic needle threading devices which use the gas carrying with exhaust form for threading the needle thread to the needle are proposed.
On the other hand, the pneumatic needle threading devices which use the gas carrying with suction form for threading the needle thread to the needle are proposed (cf: Patent document Nos. 1-6).